Heterochromatin Protein 1 (HP1) is a major regulator of chromatin structure and function. In animals, the network of proteins interacting with HP1 is mainly associated with constitutive heterochromatin marked by H3K9me3. HP1 physically interacts with the putative orthologue of the SNF2 chromatin remodeler ATRX, which controls deposition of the histone variant H3.3 in mammals. In Arabidopsis thaliana, we show that the orthologue of ATRX participates in H3.3 deposition and characterize the function of conserved domains of plant ATRX. We show that the plant Like HP1 (LHP1) interacts with ATRX through domains that evolved specifically in land plants ancestors. Interaction between ATRX and LHP1 affects the expression of a limited subset of genes controlled by the POLYCOMB REPRESSIVE COMPLEX 2 (PRC2), including the flowering time regulator FLC. In the context of flowering time, ATRX function requires the novel LHP1-interacting domain and the ATPase of the ATRX SNF2 helicase. We conclude that distinct evolutionary pathways led to interaction between ATRX and HP1 in mammals or its counterpart LHP1 in plants, resulting in distinct modes of transcriptional regulation. Overall design: 1 sample (mutant) + 1 reference sample (control)
LHP1 Interacts with ATRX through Plant-Specific Domains at Specific Loci Targeted by PRC2.
Age, Specimen part, Subject
View SamplesSelected soil-borne rhizobacteria can trigger an induced systemic resistance (ISR) that is effective against a broad spectrum of pathogens. In Arabidopsis thaliana, the root-specific transcription factor MYB72 is required for the onset of ISR, but is also associated with plant survival under conditions of iron deficiency. Here we investigated the role of MYB72 in both processes. To identify MYB72 target genes, we analyzed the root transcriptomes of wild-type Col-0, mutant myb72, and complemented 35S:FLAG-MYB72/myb72 plants in response to ISR-inducing Pseudomonas fluorescens WCS417. Five WCS417-inducible genes were misregulated in myb72 and complemented in 35S:FLAG-MYB72/myb72. Amongst these, we uncovered -glucosidase BGLU42 as a novel component of the ISR signaling pathway. Overexpression of BGLU42 resulted in constitutive disease resistance, whereas bglu42 was defective in ISR. Furthermore, we found 195 genes to be constitutively upregulated in MYB72-overexpressing roots in the absence of WCS417. Many of these encode enzymes involved in the production of iron-mobilizing phenolic metabolites under conditions of iron deficiency. We provide evidence that BGLU42 is required for their release into the rhizosphere. Together, this work highlights a thus far unidentified link between the ability of beneficial rhizobacteria to stimulate systemic immunity and mechanisms induced by iron deficiency in host plants.
β-Glucosidase BGLU42 is a MYB72-dependent key regulator of rhizobacteria-induced systemic resistance and modulates iron deficiency responses in Arabidopsis roots.
Specimen part
View SamplesTo study differentially expressed genes in neuro-ectodermal cell lines
Downregulation of Axl in non-MYCN amplified neuroblastoma cell lines reduces migration.
Sex, Specimen part
View SamplesWe used a mouse strain in which one Tbx3 gene was replaced with the yellow fluorescent protein variant Venus. Luminal cells had either very high Tbx3 promoter activity or not at all.
Transcriptional repressor Tbx3 is required for the hormone-sensing cell lineage in mammary epithelium.
No sample metadata fields
View SamplesLow reduced red:far-red ratio [R:FR] signaling through phytochromes induces shade avoidance responses, including petiole elongation. Jasmonic acid-mediated defense against herbivores and pathogens is inhibited under these conditions.
Low red/far-red ratios reduce Arabidopsis resistance to Botrytis cinerea and jasmonate responses via a COI1-JAZ10-dependent, salicylic acid-independent mechanism.
Specimen part, Treatment
View SamplesAcute Lymphoblastic Leukemia (ALL) in infants (<1 year of age) is characterized by a high incidence of MLL translocations which is associated with a poor prognosis. Contributing to this poor prognosis is cellular drug resistance, especially to glucocorticoids like prednisolone. Although in vitro prednisolone resistance mechanisms have been proposed in pediatric ALL, it has never been studied in MLL-rearranged infant ALL, which are highly resistant to glucocorticoids in vitro and in vivo.
Elevated S100A8/S100A9 expression causes glucocorticoid resistance in MLL-rearranged infant acute lymphoblastic leukemia.
Specimen part, Disease, Disease stage
View SamplesCombined overexpression of miR-125b with miR-99a and/or miR-100 induced VCR resistance in ETV6-RUNX1-positive leukemic cells Reh.
MiR-125b, miR-100 and miR-99a co-regulate vincristine resistance in childhood acute lymphoblastic leukemia.
Disease, Cell line
View SamplesIt is now well established that bone marrow (BM) constitutes a microenvironment required for differentiation. Bone marrow mesenchymal stromal cells (BM-MSCs) strongly support MM cell growth, by producing a high level of Interleukin-6 (IL-6), a major MM cell growth factor. BM-MSCs also support osteoclastogenesis and angiogenesis. Previous studies have suggested that the direct (VLA-4, VCAM-1, CD44, VLA-5, LFA-1, syndecan-1,) and indirect interactions (soluble factors) between MM plasma cells and BM-MSCs result in constitutive abnormalities in BM-MSCs. In particular, MM BM-MSCs express less CD106 and fibronectin and more DKK1, IL-1 and TNF- as compared with normal BM-MSCs. In order to gain a global view of the differences between BM-MSCs from MM patients and healthy donors, we used gene expression profiling to identify genes associated to the transformation of MM BM-MSCs.
Evidences of early senescence in multiple myeloma bone marrow mesenchymal stromal cells.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesLow R:FR signaling through phytochromes induces shade avoidance responses, including petiole elongation. Salicylic acid-mediated defense against pathogens is inhibited under these conditions.
Perception of low red:far-red ratio compromises both salicylic acid- and jasmonic acid-dependent pathogen defences in Arabidopsis.
Age, Specimen part, Treatment
View SamplesHigh anaplastic lymphoma kinase (ALK) protein levels may be correlated with an unfavorable prognosis in neuroblastoma (NBL) patients, regardless of ALK mutation status. We therefore examined the correlation between levels of ALK, phosphorylated ALK (pALK) and downstream signaling proteins and response to ALK inhibition in a large panel of both ALK mutated (MUT) and wild type (WT) NBL cell lines. Six of the nineteen NBL cell lines had a point mutation and four an amplification of the ALK gene. ALK amplified cell lines showed similar ALK levels and ALK inhibitor sensitivity as WT cell lines and were therefore co-analyzed. The ALK mRNA (p=0.043), ALK 220 kDa (p=0.009) and ALK 140 kDa (p=0.025) protein levels were higher in ALK mutant (n=6) than WT cell lines (n=13). ALK mRNA and protein levels significantly correlated with ERK1 and ERK2 protein levels, and also with PHOX2B mRNA levels, a neural differentiation marker which is mutated in NBL. Response to ALK inhibitor TAE684 was also significantly correlated with ALK levels. ALK mutant cell lines (n=4) demonstrated a higher sensitivity towards ALK inhibitor TAE684 (14.9 fold more sensitive, p=0.004) than eight WT cell lines. These results underline the importance of ALK mutations but also ALK levels for response to ALK inhibitors in NBL cell lines. Furthermore, the strong correlation of PHOX2B and ALK suggests that neural differentiation stage may be correlated with ALK levels in neuroblastoma. These data will enhance understanding of ALK inhibitor response in future patient trials.
Anaplastic lymphoma kinase (ALK) inhibitor response in neuroblastoma is highly correlated with ALK mutation status, ALK mRNA and protein levels.
Sex, Specimen part
View Samples